[James_m4]

Hi All,

Quick background; I drive a 2006 e92 335i. 66k miles.

Now before you just presume wastegate rattle please hear me out!

When i start the car from cold i get this metalic rattle from the engine bay (cant be heard with the windows up). If i dont drive the car and let it sit there for 30secs or so the revs slowly drop from 1000rpm to say 600rpm and the rattle disappears as it passes the 700rpm point and doesnt return. It also doesnt return if i raise the revs to say 1200rpm but the second i let it drop it come back.

It only happens from a cold start (say first thing in the morning or after leaving the car for over an hour)

I have read threads about the wastegate rattle but i can rev the car upto any rpm and let the revs drop naturally but i dont get any rattle it is purely just for the first 30 secs or so whilst the engine is reving slightly higher untill it settles!

Looking through the log book the previous owner had bmw do work on the car and they have logged it as "noisey actuators, software updated to fix" so not sure what that was.

So any ideas as its very annouying and embarrasing if leaving a car park or a friends house etc they all ask me if its broken, as it is loud!

Thanks.

[vasillalov]

Heat shield rattling?

[Constant.S]

Originally Posted by jamescalland

Hi All,

Quick background; I drive a 2006 e92 335i. 66k miles.

Now before you just presume wastegate rattle please hear me out!

When i start the car from cold i get this metalic rattle from the engine bay (cant be heard with the windows up). If i dont drive the car and let it sit there for 30secs or so the revs slowly drop from 1000rpm to say 600rpm and the rattle disappears as it passes the 700rpm point and doesnt return. It also doesnt return if i raise the revs to say 1200rpm but the second i let it drop it come back.

It only happens from a cold start (say first thing in the morning or after leaving the car for over an hour)

I have read threads about the wastegate rattle but i can rev the car upto any rpm and let the revs drop naturally but i dont get any rattle it is purely just for the first 30 secs or so whilst the engine is reving slightly higher untill it settles!

Looking through the log book the previous owner had bmw do work on the car and they have logged it as "noisey actuators, software updated to fix" so not sure what that was.

So any ideas as its very annouying and embarrasing if leaving a car park or a friends house etc they all ask me if its broken, as it is loud!

Thanks.

Get someone else to start the car for you while cold to check if the sound does come from the engine bay and not Under by some lose exhaust part, it might be Ratling from the catalyst or the Sound valve that is located near the tips of the exhaust or maybe from the heat shield/insulation in the engine bay area... Just a thought...

[fisherbln]

My wastegates (and turbos) are being replaced at the dealer at this very moment for what sounds like you are describing above. If you can feather your throttle slightly after cold start to encourage it to rattle even more, then you have the same thing I do.

Good luck getting BMW to step up to the plate to fix it though. I had to wait for my warranty to end and then (magically) the BMW dealer could hear it (two trips just 2K miles prior and they claimed they could hear nothing) and diagnosed it as wastegates. Charged it to my aftermarket warranty company (thank god). I am going to report the whole ordeal to the attorney general, but I doubt it will go anywhere.

[James_m4]

I have had it started tonight by another person and its deffo coming from the engine bay i can clearly hear it from the the engine bay with the hood up...... sounds like its coming from the left hand side of the engine. Funny thing is i had a mini cooper s before this and it had the same problem it was re-nound for the minis as they had a faulty pre-tensioner on the chain than made it easily wobble and clatter, this sounds the same.

To clarify i have also checked the exhaust and it makes the noise whether the flap is open or closed.

Surely if it was the wastegates then they would make the noise whenever the cars revs went up and then down as discribed by others, and it would happen all the time? Mine only does it for like 30secs at start up then it goes never to be heard again.

Any other thoughts?

[fisherbln]

Originally Posted by jamescalland

Surely if it was the wastegates then they would make the noise whenever the cars revs went up and then down as discribed by others, and it would happen all the time? Mine only does it for like 30secs at start up then it goes never to be heard again.

Mine only did/does it on cold start for a few minutes until the engine warmed up. My theory was that after the turbos/actuators expanded from heat, they weren't as far out of tolerance, hence no more noise after the car was warm.

[UCF 335]

I have the same noise...BMW says they can't hear anything...

Im curious to see if u find the answer.

[James_m4]

Originally Posted by goblue8

I have the same noise...BMW says they can't hear anything...

Im curious to see if u find the answer.

Hmmmm i dunno!

Reading the stuff poted by "Mr.5" i am going to try his actuating arm fix. I think thats what it is...... the rod has loosen off causing the actuator to rattle slightly. Tighten this up and problem is solved.

Will give it ago when its not raining out!

Thanks

[Constant.S]

Originally Posted by jamescalland

I have had it started tonight by another person and its deffo coming from the engine bay i can clearly hear it from the the engine bay with the hood up...... sounds like its coming from the left hand side of the engine. Funny thing is i had a mini cooper s before this and it had the same problem it was re-nound for the minis as they had a faulty pre-tensioner on the chain than made it easily wobble and clatter, this sounds the same.

To clarify i have also checked the exhaust and it makes the noise whether the flap is open or closed.

Surely if it was the wastegates then they would make the noise whenever the cars revs went up and then down as discribed by others, and it would happen all the time? Mine only does it for like 30secs at start up then it goes never to be heard again.

Any other thoughts?

Probably some lose part of the lower protection shield or (my best guess) some lose part on the exhaust (had this problem on my Audi S3) that the vibrations when the engine starts trigger... If it goes away after a few seconds it isnt the wastegates and it shoulndt be something serious. Just stop by your local BMW dealer whenever ur in the area and ask around.

[Forcefed3]

Sounds like wastegate rattle to me. It seems like anything loose would keep rattling, take it in.